Basically once 3.7 is out (which is soon), CPython3 will finally be broadly faster than CPython2.7.
Interpreter startup time is still annoying though. I really wonder what the right strategy for addressing that is. Like honestly 2.7 is faster than 3.x, but 2.7 CLI tools still feel silly to use.
If you are doing raw number crunching you shouldn't be using python in the first place, the whole idea of python is that it makes it easier to write better algorithms lowering your big-O, or use python for the lightweight orchestration and call into native processing libs or external processes such as numpy for the heavy lifting. Same goes for distributed computing which is becoming much more popular; asyncio, await, and other improvements from py3 makes it easier to write fast and robust distributed code, improving your overall application performance.
Basically once 3.7 is out (which is soon), CPython3 will finally be broadly faster than CPython2.7.
Interpreter startup time is still annoying though. I really wonder what the right strategy for addressing that is. Like honestly 2.7 is faster than 3.x, but 2.7 CLI tools still feel silly to use.